Commit Graph

21 Commits

Author SHA1 Message Date
Alex Langford 1d2a62afaf Re-submit "[lldb] Filter DIEs based on qualified name where possible"
This reverts commit 967df65a36.

This fixes test/Shell/SymbolFile/NativePDB/find-functions.cpp. When
looking up functions with the PDB plugins, if we are looking for a
full function name, we should use `GetName` to populate the `name`
field instead of `GetLookupName` since `GetName` has the more
complete information.
2022-08-04 15:52:27 -07:00
Alex Langford 967df65a36 Revert "[lldb] Filter DIEs based on qualified name where possible"
This reverts commit befa77e59a.

Looks like this broke a SymbolFileNativePDB test. I'll investigate and
resubmit with a fix soon.
2022-08-04 11:52:30 -07:00
Alex Langford befa77e59a [lldb] Filter DIEs based on qualified name where possible
Context:
When setting a breakpoint by name, we invoke Module::FindFunctions to
find the function(s) in question. However, we use a Module::LookupInfo
to first process the user-provided name and figure out exactly what
we're looking for. When we actually perform the function lookup, we
search for the basename. After performing the search, we then filter out
the results using Module::LookupInfo::Prune. For example, given
a:🅱️:foo we would first search for all instances of foo and then filter
out the results to just names that have a:🅱️:foo in them. As one can
imagine, this involves a lot of debug info processing that we do not
necessarily need to be doing. Instead of doing one large post-processing
step after finding each instance of `foo`, we can filter them as we go
to save time.

Some numbers:
Debugging LLDB and placing a breakpoint on
llvm::itanium_demangle::StringView::begin without this change takes
approximately 70 seconds and resolves 31,920 DIEs. With this change,
placing the breakpoint takes around 30 seconds and resolves 8 DIEs.

Differential Revision: https://reviews.llvm.org/D129682
2022-08-04 11:18:08 -07:00
Jeffrey Tan 7b81192d46 Introduce new symbol on-demand for debug info
This diff introduces a new symbol on-demand which skips
loading a module's debug info unless explicitly asked on
demand. This provides significant performance improvement
for application with dynamic linking mode which has large
number of modules.
The feature can be turned on with:
"settings set symbols.load-on-demand true"

The feature works by creating a new SymbolFileOnDemand class for
each module which wraps the actual SymbolFIle subclass as member
variable. By default, most virtual methods on SymbolFileOnDemand are
skipped so that it looks like there is no debug info for that module.
But once the module's debug info is explicitly requested to
be enabled (in the conditions mentioned below) SymbolFileOnDemand
will allow all methods to pass through and forward to the actual SymbolFile
which would hydrate module's debug info on-demand.

In an internal benchmark, we are seeing more than 95% improvement
for a 3000 modules application.

Currently we are providing several ways to on demand hydrate
a module's debug info:
* Source line breakpoint: matching in supported files
* Stack trace: resolving symbol context for an address
* Symbolic breakpoint: symbol table match guided promotion
* Global variable: symbol table match guided promotion

In all above situations the module's debug info will be on-demand
parsed and indexed.

Some follow-ups for this feature:
* Add a command that allows users to load debug info explicitly while using a
  new or existing command when this feature is enabled
* Add settings for "never load any of these executables in Symbols On Demand"
  that takes a list of globs
* Add settings for "always load the the debug info for executables in Symbols
  On Demand" that takes a list of globs
* Add a new column in "image list" that shows up by default when Symbols On
  Demand is enable to show the status for each shlib like "not enabled for
  this", "debug info off" and "debug info on" (with a single character to
  short string, not the ones I just typed)

Differential Revision: https://reviews.llvm.org/D121631
2022-04-26 10:42:06 -07:00
Jaroslav Sevcik f968bd77bb Reland "[lldb/DWARF] Only match mangled name in full-name function lookup (with accelerators)"
Summary:

In the spirit of https://reviews.llvm.org/D70846, we only return functions with
matching mangled name from Apple/DebugNamesDWARFIndex::GetFunction if
eFunctionNameTypeFull is requested.

This speeds up lookup in the presence of large amount of class methods of the
same name (a typical examples would be constructors of templates with many
instantiations or overloaded operators).

Reviewers: labath, teemperor

Reviewed By: labath, teemperor

Subscribers: aprantl, arphaman, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D73191
2021-08-04 12:50:13 +02:00
Jan Kratochvil d482fe2add [nfc] [lldb] DWARF callbacks: DIERef -> DWARFDIE
Pavel Labath wrote in D73206:
The internal representation of DebugNames and Apple indexes is fixed by
the relevant (pseudo-)standards, so we can't really change it. The
question is how to efficiently (and cleanly) convert from the internal
representation to some common thing. The conversion from AppleIndex to
DIERef is trivial (which is not surprising as it was the first and the
overall design was optimized for that). With debug_names, the situation
gets more tricky. The internal representation of debug_names uses
CU-relative DIE offsets, but DIERef wants an absolute offset. That means
the index has to do more work to produce the common representation. And
it needs to do that for all results, even though a lot of the index
users are really interested only in a single entry. With the switch to
user_id_t, _all_ indexes would have to do some extra work to encode it,
only for their users to have to immediately decode it back. Having
a iterator/callback based api would allow us to minimize the impact of
that, as it would only need to happen for the entries that are really
used. And /I think/ we could make it interface returns DWARFDies
directly, and each index converts to that using the most direct approach
available.

Jan Kratochvil:
It also makes all the callers shorter as they no longer need to fetch
DWARFDIE from DIERef (and handling if not found by ReportInvalidDIERef)
but the callers are already served DWARFDIE which they need.
In some cases the DWARFDIE had to be fetched both by callee (DWARFIndex
implementation) and caller.

Differential Revision: https://reviews.llvm.org/D77970
2020-04-22 17:11:50 +02:00
Jan Kratochvil 5e04b5f2fa [nfc] [lldb] Introduce DWARF callbacks (fixed-up)
As requested by @labath in https://reviews.llvm.org/D73206#1949516
providing DWARF index callbacks refactorization.

It is a re-landing of the patch with a regression fix the previous
commit had.

Differential Revision: https://reviews.llvm.org/D77327
2020-04-15 23:40:54 +02:00
Jan Kratochvil 9289f34390 Revert "[nfc] [lldb] Introduce DWARF callbacks"
This reverts commit bd47c470d1.

It broke Green Dragon, reason is unknown to me so far:
  http://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/15323/consoleFull

Differential Revision: https://reviews.llvm.org/D77327
2020-04-15 15:12:59 +02:00
Jan Kratochvil bd47c470d1 [nfc] [lldb] Introduce DWARF callbacks
As requested by @labath in https://reviews.llvm.org/D73206#1949516
providing DWARF index callbacks refactorization.

Differential Revision: https://reviews.llvm.org/D77327
2020-04-15 10:37:38 +02:00
Raphael Isemann f9568a9549 [lldb][NFC] Make all CompilerDeclContext parameters references instead of pointers
Summary:
All of our lookup APIs either use `CompilerDeclContext &` or `CompilerDeclContext *` semi-randomly it seems.
This leads to us constantly converting between those two types (and doing nullptr checks when going from
pointer to reference). It also leads to the confusing situation where we have two possible ways to express
that we don't have a CompilerDeclContex: either a nullptr or an invalid CompilerDeclContext (aka a default
constructed CompilerDeclContext).

This moves all APIs to use references and gets rid of all the nullptr checks and conversions.

Reviewers: labath, mib, shafik

Reviewed By: labath, shafik

Subscribers: shafik, arphaman, abidh, JDevlieghere, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D74607
2020-02-18 08:58:36 +01:00
Pavel Labath d8de349951 Revert "[lldb/DWARF] Only match mangled name in full-name function lookup (with accelerators)"
This reverts commit 1b12766883 because of
breaking the mac test suite.

I'm not certain this is the cause because of a concurrent build breakage
which masked this problem, but the failure messages are related to
symbol lookup, which makes this very likely.
2020-01-28 13:46:43 +01:00
Jaroslav Sevcik 1b12766883 [lldb/DWARF] Only match mangled name in full-name function lookup (with accelerators)
Summary:
In the spirit of https://reviews.llvm.org/D70846, we only return functions with matching mangled name from Apple/DebugNamesDWARFIndex::GetFunction if eFunctionNameTypeFull is requested.

This speeds up lookup in the presence of large amount of class methods of the same name (a typical examples would be constructors of templates with many instantiations or overloaded operators).

Reviewers: labath

Reviewed By: labath

Subscribers: aprantl, arphaman, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D73191
2020-01-28 12:16:02 +01:00
Raphael Isemann 808142876c [lldb][NFC] Fix all formatting errors in .cpp file headers
Summary:
A *.cpp file header in LLDB (and in LLDB) should like this:
```
//===-- TestUtilities.cpp -------------------------------------------------===//
```
However in LLDB most of our source files have arbitrary changes to this format and
these changes are spreading through LLDB as folks usually just use the existing
source files as templates for their new files (most notably the unnecessary
editor language indicator `-*- C++ -*-` is spreading and in every review
someone is pointing out that this is wrong, resulting in people pointing out that this
is done in the same way in other files).

This patch removes most of these inconsistencies including the editor language indicators,
all the different missing/additional '-' characters, files that center the file name, missing
trailing `===//` (mostly caused by clang-format breaking the line).

Reviewers: aprantl, espindola, jfb, shafik, JDevlieghere

Reviewed By: JDevlieghere

Subscribers: dexonsmith, wuzish, emaste, sdardis, nemanjai, kbarton, MaskRay, atanasyan, arphaman, jfb, abidh, jsji, JDevlieghere, usaxena95, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D73258
2020-01-24 08:52:55 +01:00
Pavel Labath 3b9269882e DWARF: Add "dwo_num" field to the DIERef class
Summary:
When dwo support was introduced, it used a trick where debug info
entries were referenced by the offset of the compile unit in the main
file, but the die offset was relative to the dwo file. Although there
was some elegance to it, this representation was starting to reach its
breaking point:
- the fact that the skeleton compile unit owned the DWO file meant that
  it was impossible (or at least hard and unintuitive) to support DWO
  files containing more than one compile unit. These kinds of files are
  produced by LTO for example.
- it made it impossible to reference any DIEs in the skeleton compile
  unit (although the skeleton units are generally empty, clang still
  puts some info into them with -fsplit-dwarf-inlining).
- (current motivation) it made it very hard to support type units placed
  in DWO files, as type units don't have any skeleton units which could
  be referenced in the main file

This patch addresses this problem by introducing an new
"dwo_num" field to the DIERef class, whose purpose is to identify the
dwo file. It's kind of similar to the dwo_id field in DWARF5 unit
headers, but while this is a 64bit hash whose main purpose is to catch
file mismatches, this is just a smaller integer used to indentify a
loaded dwo file. Currently, this is based on the index of the skeleton
compile unit which owns the dwo file, but it is intended to be
eventually independent of that (to support the LTO use case).

Simultaneously the cu_offset is dropped to conserve space, as it is no
longer necessary.  This means we can remove the "BaseObjectOffset" field
from the DWARFUnit class. It also means we can remove some of the
workarounds put in place to support the skeleton-unit+dwo-die combo.
More work is needed to remove all of them, which is out of scope of this
patch.

Reviewers: JDevlieghere, clayborg, aprantl

Subscribers: mehdi_amini, dexonsmith, arphaman, lldb-commits

Differential Revision: https://reviews.llvm.org/D63428

llvm-svn: 364009
2019-06-21 07:56:50 +00:00
Pavel Labath 78b2cf71f5 DWARFIndex: s/ReportInvalidDIEOffset/ReportInvalidDIERef
In a dwo/debug_types world, the die offset is not enough to uniquely
idendify a debug info entry. Pass the the entire DIERef object instead.

This is technically NFC, because only AppleIndex implemented this
method (and there, the die offset *is* enough for unique
identification). However, this makes the code simpler, and simplifies
some of the follow-up patches.

llvm-svn: 363373
2019-06-14 12:01:18 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Pavel Labath 257ff33989 DebugNamesDWARFIndex: Implement GetFunctions method
Summary:
This patch implements the non-regex variant of GetFunctions. To share
more code with the Apple implementation, I've extracted the common
filtering code from that class into a utility function on the DWARFIndex
base class.

The new implementation also searching the accelerator table multiple
times -- previously it could happen that the apple table would return
the same die more than once if one specified multiple search flags in
name_type_mask. This way, I separate table iteration from filtering, and
so we can be sure each die is inserted at most once.

Reviewers: clayborg, JDevlieghere

Subscribers: aprantl, lldb-commits

Differential Revision: https://reviews.llvm.org/D47881

llvm-svn: 334273
2018-06-08 09:10:31 +00:00
Pavel Labath 6de9c79e71 DWARFIndex: more GetFunctions cleanup
This applies similar simplification as r334004, only it touches the
regex version of the method.

llvm-svn: 334012
2018-06-05 12:13:22 +00:00
Pavel Labath b13f033818 Reland "[DWARF] Extract indexing code into a separate class hierarchy"
After this commit, the xcode project will need to be updated to include
the new files added here.

llvm-svn: 332841
2018-05-21 14:12:52 +00:00
Amara Emerson 29b8df607e Revert "[DWARF] Extract indexing code into a separate class hierarchy"
This reverts commit r332719 due to breaking this green dragon build:
http://green.lab.llvm.org/green/job/lldb-xcode/6644

llvm-svn: 332730
2018-05-18 15:59:42 +00:00
Pavel Labath 1237095b3c [DWARF] Extract indexing code into a separate class hierarchy
Summary:
This places the `if(m_using_apple_tables)` branches inside the
SymbolFileDWARF class behind an abstract DWARFIndex class. The class
currently has two implementations:
- AppleIndex, which searches using .apple_names and friends
- ManualIndex, which searches using a manually built index

Most of the methods of the class are very simple, and simply extract the
list of DIEs for the given name from the appropriate sub-table. The main
exception are the two GetFunctions overloads, which take a couple of
extra paramenters, including some callbacks. It was not possible to
split these up the same way as other methods, as here we were doing a
lot of post-processing on the results. The post-processing is similar
for the two cases, but not identical. I hope to factor these further in
separate patches.

Other interesting methods are:
- Preload(): do any preprocessing to make lookups faster (noop for
  AppleIndex, forces a build of the lookup tables for ManualIndex).
- ReportInvalidDIEOffset(): Used to notify the users of an invalid index
  (prints a message for AppleIndex, noop for ManualIndex).
- Dump(): dumps the index state (noop for AppleIndex, prints the lookup
  tables for ManualIndex).

Reviewers: clayborg, JDevlieghere

Subscribers: mgorny, aprantl, lldb-commits

Differential Revision: https://reviews.llvm.org/D46889

llvm-svn: 332719
2018-05-18 14:15:46 +00:00